A comparison of basal reflectivity and ice velocity in East Antarctica

Ground-based radio echo sounding data acquired along the 1700 km US-ITASE traverse have been used to determine ice attenuation and relative basal reflectivity across the major catchments funneling ice from East Antarctica to the Ross Ice Shelf. We find that basal reflectivity varies locally by up to...

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Bibliographic Details
Published in:The Cryosphere
Main Authors: R. W. Jacobel, K. E. Lapo, J. R. Stamp, B. W. Youngblood, B. C. Welch, J. L. Bamber
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2010
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Online Access:https://doi.org/10.5194/tc-4-447-2010
https://doaj.org/article/956f075a20f94b40bfb6b4659dc7f3fe
Description
Summary:Ground-based radio echo sounding data acquired along the 1700 km US-ITASE traverse have been used to determine ice attenuation and relative basal reflectivity across the major catchments funneling ice from East Antarctica to the Ross Ice Shelf. We find that basal reflectivity varies locally by up to 40 dB which we interpret as due to changes in the phase state at the bed. Some, though not all, areas of high local reflectivity are observed to have flat-lying bed reflections indicative of sub-glacial lakes. We compare basal reflectivity to ice balance velocity and find a general association of higher flow speeds with high radar reflection strength. This set of observations from two independent remotely sensed geophysical data sets extends the range of field observations to the interior of East Antarctica and confirms the importance of basal lubrication on modulating the ice dynamics of the largest ice sheet on the planet.